Control for infinitely variable transmission



April 9, 1935; w. D. GOVE CONTROL FOR INDEFINITELY VARIABLE TRANSMISSION Filed Dec. 12, 1932 Z m W W 1 W w M Mr 9 I 7 my 2 I S fl a O J V Il MW] v! {xv a, Q X V fl u m v 5 a 0 i w V ,1 a k 1 2 5 J s. I o w M a v ....F/ x H IN... g M or mm. 0 r N... [I O fl 4 6. O Iv 7 r I o a 0..

o n m m 0 1 M 7 I m I M TR) 0 .Hl-ll M Patented Apr. 9, .1935

UNITED STATES PATENT [OFFICE CONTROL FOR INFINITELY VARIABLE TRANSMISSION Winfield D. Gove, Flint, Mich, assignor, by mesne assignments, to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application December 12, 1932, Serial No. 646,758

6 Claims.

type.

In transmission devices of this kind it has been proposed to employ a movable member to shift the position of the rollers relative to the driving and driven discs; to employ an arm rotatable by a governor responsive to the driving or driven shafts, preferably the former, and to make use of linkage between the governor actuated arm and the roller shifting member to change the driving ratio.

My invention has for its object an improvement in such linkage which consists in the use of cam means between the governor actuated arm and the shifting member.

More specifically the cam means employs a swinging-member having a fixed pivot, said swinging member constructed to be engaged and rotated by the governor actuating arm through the instrumentality of a camming surface on the swinging member, and a differential lever which latter is operably connected to the ratio shifting member.

In such transmissions it is also known to employ dashpot devices to check the rate of shifting. My invention provides an improved sealed dashpot operated by a pivoted arm articulated to a short piston, which latter'has a spherical contour in contact with the dashpot cylinder. The articulating points are chosen to give minimum motion to a sealing boot and to provide a minimum change in the inside volume of the dashpot due to the motion of the piston. It is alsowithinthe scope of the invention to employ a dashpot construction having a sealing metal bellows. It is also a part of the invention to employ aliquid such as kerosene which shall have small change in viscosity with changes in temperature.

Other objects and advantages will be understood'from the following description.

Fig. 1 is a view in side elevation of the motor and transmission of a motor vehicle, my control mechanism being associated therewith.

Fig. 2 is a view inside elevation of the control mechanism mounted on the wall of the trans- 'tent carried by arm II. A cable 'IB'is'connected stops 3 and I3 in its idling and full open positions respectively. The throttle lever is connected by a rod |5 to a mid portion ll of a lever l9 pivoted at 2| to the dash 23. A differential lever 25 is pivoted at one end to the free end 5 of lever l9. Its other end is connected by a link 21 to a lever arm 29 which is movable in a counterclockwise direction in changing the driving ratio to low speed as will be explained below. The accelerator pedal 3|. is connected by a link 33 to a mid point of lever 25. A spring 35 anchored at one end and connected to link l5 at the other operates to hold the throttle in its idling position.

The engine functions to drive the vehicle through change speed mechanism including, in the illustrated embodiment, discs (driving and driven) one of which is shown at 31 and rollers such as 39. An input shaft governor (not shown) rocks an arm 4| in a clockwise direction as the speed of the shaft increases. A roller 43 on the end of arm 4| moves in a cam slot 45 of a swin ing member 41, rotating on a fixed pivot 49. At 5| on lever 41 is the pivot of a differential lever 53. This lever has a slot 55 within which is a roller 51 on the end of a link 59, the latter piv oted on the end of a lever arm 5| carried by shaft 63, this being the shaft to which is secured arm 29 referred to above. Rotatable about the axis of shaft 63 is a hub 65 having an arm 61 connected by a link 69 to the arm 59. Hub 65 has another arm A plate 13 is fixedly secured in position by fastening means 15, and has openings 11 to be engaged by a suitable spring deto arm H and terminates in a button 8| prefer 3 ably on the instrument panel 83. By this means operation of the button rotates the hub 65 which,

' through the instrumentality of link 69, swings the "link 59, its end moving in slot 55, thus changing tlledeverage whereby the governor arm 4| rocks thediiferential lever 53. Also, the accelera tor pedal 3|, after; having opened'the throttle to its maximum position, may rock lever 25 and through the link 21 also rocklever'arm' 29. Such rocking of 29 actuates the-diiferentiallever 53 through the link'59, turning the difierenti'al lever about its pivot 5| with the swingingmember 4T. 'I'hislast described'movement of the differential" lever through the depressionof-the accelerator pedal operates toshift the gear ratio toward low speed as will be explained.

The rollers 39 are rocked'by movements'of the lever 53. These movements: of lever 53 1iiay-'be-i I occasioned by'the governoractuated arm 4| or by the swinging of arm 6| through the. instrumentality of the accelerator pedal as explained above. The differential lever 53 performs the shifting movement by means of a rod 81 attached to the lever 53; a rod 89 attached to mechanism generally indicated as 9| operably connected to thefriction roller system, and yielding means between said parts 81 and 89 not shown but enclosed in housing 93 which is attached to part 89.

Pivoted to the housing 93 is a link terminally pivoted to a double arm lever 91, rotatable about a fixed pivot 99. The work arm of lever 91 is curved as shown by numeral IOI. It enters a dashpot constituted by a casing I03 pivoted at I05 and. also including an arcuate neck portion I01 secured thereto. A sealing boot I09 connects the lever 81 to the opening of part I01. The piston I I I has a spherical contour and is preferably provided with a restricted passage extending therethrough. It is pivoted at II3 to the aforesaid lever arm IN. The part I01 has a lug I15 provided with an opening II1. A stop pin II9 extends through the opening II1 and limits the swinging of the dashpot about its pivot I05. A cable I 2| is connected by'a coupling I23 with a spring I25 which spring is attached to the lug I I5. This cable is preferably attached at its other end to the brake pedal I21 to the end that the application of the brake may rock the dashpot casing relative to its piston, thereby permitting the flow, of fluid around the periphery of the piston and prevent the effect of the dashpot in retarding the shift to low speed when the brake is applied to stop the vehicle. The points of articulation associated with the dashpot are such as to permit its action without materially flexing the sealing boot and to prevent any considerable change in the cubical contents within the dashpot. The spring I25 is provided in the linkage in order that the brake pedal I21 may be further depressed after the dashpot has moved sufliciently to engage the stop II9.

Spring I29 is anchored on pivot pin I05 and is attached to the end of lever GI. This spring is of such strength relative to spring 35 that it ofiers suflicient resistance to the rotation of lever 25 through the link 21 to ensure that the throttle may be opened to its widest position before the accelerator pedaloperates to rock the differential lever. It will be understood that this rocking of the differential lever is such as to tend to force the driving ratio toward low speed position and thereby secure maximum acceleration with the engine at full throttle.

In Fig. 3 is shown another form of dashpot. In this form a cylinder I 02 is pivotally anchored by 9. lug I04. Bellows preferably of metal and marked I06 and I08 are connected to the otherwise open ends of cylinder I02. Discs or heads H0 and H2 are connected to the inner ends of the bellows. A rod I I 4 is connected to these heads, and extends through an'intermediate partition I I6. One end I I8 of the rod I I4 is connected to a suitable mechanism (not shown) such as a lever 91 attached to a connecting link such as 95 of Fig. 2, which link is pivotally attached to they cylinder 93 asbefore explained. Partition II6 has one or more restricted openings I20 whereby the shifting of the rollers to change ratios is retarded. A cover I22 of cup shape encloses a boss I24 provided on the wall of the cylinder adjacent the partition. A

disc I 26 overlies the boss within the cover I22 and is connected to the boss by a bellows I28. Two passages I30 and I32 extend through the boss and connect the chamber within the bellows with opposite sides of the partition. One of these passages is closed by a spherical closure member I34 which is engaged by the disc I26. Welded to the cover I22 is a sleeve I36 within which slides a cup I38 backed by a spring I 40 which engages an abutment I42. The cup I38 is attached to the disc I26. Extending through the spring I40 is a rod I44. This rod has a head I46 within the cup. The rod I44 may be a part of or may be attached to the end of a cable. This cable will be secured to the brake lever at I21 as before. With this form of dashpot the restricted opening in the partition enables the device to prevent too rapid shifting. However, when the brake is used to check the speed of the vehicle the disc I26 is lifted and the spherical member may then cease to close the passage it controls and the dashpot no longer restricts the shifting of the gear ratio to low speed.

It will be understood that the spring device (not shown) within housing 93 may be said to be force limiting in that it limits the force mechanically applied to the housing 93 and consequently determines the force action on the piston of the.

dashpot. With the force thus predetermined and the opening in the piston fixed, the dashpot ensures a predetermined 'rate of shift.

I claim:

1. In a change speed transmission for vehicles an infinitely variable speed ratio changing mechanism, a governor operated member, movable mechanism operable to change the speed ratio in response to each increment of its movement, cam means therebetween operably connected to said governor operated member and said mechanism.

comprising a swinging member operably connected to and for movement by said governor operated member, a lever pivoted-to said swinging member at a pivot removed from its fulcrum,

said lever being connected to said mechanism,

said operable connection between the swinging member and the governor operated member including a cammed slot whereby the rate of movement of the lever by the governor operated member is determined.

3. In a change speed transmission for vehicles, a governor operated member, mechanism to change the speed ratio, cam means therebetween operably connected to said governor operated member and said mechanism, said cam means comprising a swinging member operably connected to and for movement by said governor operatedmember, a lever pivoted to said swinging member at a pivot removed from its fulcrum,

said lever being connected to said mechanism,

said operable connection between the swinging member and the governor operated member, in-

cluding a cammed slot whereby the rate of movement of the lever by the governor operated member is determined, said lever being a differential lever and manually operable means to rotate said lever about its pivot with the swinging member whereby manual change'of ratio may be effected. 4

4. In a change speed transmission for vehicles, a governor operated member, mechanism to change the speed ratio, cam means'therebetween nected to and for movement by said governor operated member, a lever pivoted to said swinging member at a pivot removed from its fulcrum. said lever being connected to said mechanism.

said operable connection between the 8! in:

member and the governor operated member including a cammed slot whereby the rate of movement of the lever by the governor operated member is determined, said lever being a diflerential lever, manually operable means to rotate said lever about its pivot with the sw nli i member whereby manual change 0! ratio may be effected. and another manually operable member to adjust the fulcrum oi' said lever.

5. For use with an infinitely variable transmission, means to shift the driving ratio, a dashpot to retard the rate 0! ratio changes, said dashpot comprising a cylinder, a piston having a spherical contour and means to tilt said piston to cut out the dashpot resistance to ratio chang- 6. For use with an infinitely variable transmission. means to shift the driving ratio, a dashpot to retard the rate of change, said dashpot com:- prising a. pivoted casing. a reciprocable piston therein-having a spherical contour, means to change the axis of the dashpot relative to the axis 01' the piston, lever means operably connected to said means for changing the driving ratio and to said piston whereby the piston is reciprocated.

WINFIELD D. GOVE. 

